diff --git a/sqlcon/dockertest/test_helper.go b/sqlcon/dockertest/test_helper.go
index 97664ee9..05008732 100644
--- a/sqlcon/dockertest/test_helper.go
+++ b/sqlcon/dockertest/test_helper.go
@@ -31,14 +31,6 @@ import (
 	"github.com/ory/x/stringsx"
 )
 
-// atexit := atexit.NewOnExit()
-// atexit.Add(func() {
-//	dockertest.KillAll()
-// })
-// atexit.Exit(testMain(m))
-
-// func WrapCleanup
-
 type dockerPool interface {
 	Purge(r *dockertest.Resource) error
 	Run(repository, tag string, env []string) (*dockertest.Resource, error)
@@ -46,33 +38,30 @@ type dockerPool interface {
 }
 
 var (
-	resources = []*dockertest.Resource{}
 	pool      dockerPool
+	resources []*dockertest.Resource
+	mux       sync.Mutex
 )
 
-func getPool() (dockerPool, error) {
-	if pool != nil {
-		return pool, nil
-	}
+func init() {
 	var err error
 	pool, err = dockertest.NewPool("")
-	return pool, err
-}
-
-// KillAllTestDatabases deletes all test databases.
-func KillAllTestDatabases() {
-	pool, err := getPool()
 	if err != nil {
 		panic(err)
 	}
+}
 
+// KillAllTestDatabases deletes all test databases.
+func KillAllTestDatabases() {
+	mux.Lock()
+	defer mux.Unlock()
 	for _, r := range resources {
 		if err := pool.Purge(r); err != nil {
 			log.Printf("Failed to purge resource: %s", err)
 		}
 	}
 
-	resources = []*dockertest.Resource{}
+	resources = nil
 }
 
 // Register sets up OnExit.
@@ -154,14 +143,11 @@ func ConnectPop(t require.TestingT, url string) (c *pop.Connection) {
 // ## PostgreSQL ##
 
 func startPostgreSQL(version string) (*dockertest.Resource, error) {
-	pool, err := getPool()
-	if err != nil {
-		return nil, errors.Wrap(err, "Could not connect to docker")
-	}
-
-	resource, err := pool.Run("postgres", stringsx.Coalesce(version, "11.8"), []string{"PGUSER=postgres", "POSTGRES_PASSWORD=secret", "POSTGRES_DB=postgres"})
+	resource, err := pool.Run("postgres", stringsx.Coalesce(version, "16"), []string{"PGUSER=postgres", "POSTGRES_PASSWORD=secret", "POSTGRES_DB=postgres"})
 	if err == nil {
+		mux.Lock()
 		resources = append(resources, resource)
+		mux.Unlock()
 	}
 	return resource, err
 }
@@ -235,14 +221,9 @@ func ConnectToTestPostgreSQLPop(t testing.TB) *pop.Connection {
 // ## MySQL ##
 
 func startMySQL(version string) (*dockertest.Resource, error) {
-	pool, err := getPool()
-	if err != nil {
-		return nil, errors.Wrap(err, "Could not connect to docker")
-	}
-
 	resource, err := pool.RunWithOptions(&dockertest.RunOptions{
 		Repository: "mysql",
-		Tag:        stringsx.Coalesce(version, "8.0.26"),
+		Tag:        stringsx.Coalesce(version, "8.0"),
 		Env: []string{
 			"MYSQL_ROOT_PASSWORD=secret",
 			"MYSQL_ROOT_HOST=%",
@@ -251,7 +232,9 @@ func startMySQL(version string) (*dockertest.Resource, error) {
 	if err != nil {
 		return nil, err
 	}
+	mux.Lock()
 	resources = append(resources, resource)
+	mux.Unlock()
 	return resource, nil
 }
 
@@ -327,18 +310,15 @@ func ConnectToTestMySQLPop(t testing.TB) *pop.Connection {
 // ## CockroachDB
 
 func startCockroachDB(version string) (*dockertest.Resource, error) {
-	pool, err := getPool()
-	if err != nil {
-		return nil, errors.Wrap(err, "Could not connect to docker")
-	}
-
 	resource, err := pool.RunWithOptions(&dockertest.RunOptions{
 		Repository: "cockroachdb/cockroach",
-		Tag:        stringsx.Coalesce(version, "v20.2.5"),
+		Tag:        stringsx.Coalesce(version, "latest-v24.2"),
 		Cmd:        []string{"start-single-node", "--insecure"},
 	})
 	if err == nil {
+		mux.Lock()
 		resources = append(resources, resource)
+		mux.Unlock()
 	}
 	return resource, err
 }